GeneDx Holdings Corp. (NASDAQ: WGS) experienced a dramatic after-hours plunge of 45.53% following the release of its first-quarter 2026 financial results.

The rare disease genomics firm reported Q1 revenue of $102.3 million, which represented a 17% year-over-year increase but fell short of the analyst consensus estimate of approximately $113 million. Furthermore, the company's adjusted earnings per share of -$0.28 missed the expected -$0.01, and it reported a significant GAAP net loss of $63.3 million for the quarter.

Investor sentiment was heavily impacted by the company's decision to substantially lower its full-year 2026 revenue guidance. Management now expects revenue in the range of $475 million to $490 million, a sharp reduction from the previous outlook of $540 million to $555 million. While the company noted strong volume growth in its core exome and genome testing business, the revised forecast and earnings miss prompted a severe sell-off in the post-market session.